PHP comes with many built-in URL-style wrapper protocols that can be used for file system functions like fopen(), copy(), file_exists() and filesize(). In addition to these packaging protocols, custom packaging protocols can also be registered through stream_wrapper_register().
Note: The URL syntax used to describe an encapsulation protocol only supports scheme://... syntax. scheme:/ and scheme: syntax are not supported.
file:// — access the local file system
http:// — access HTTP(s) URLs
ftp:// — access FTP(s) URLs
php:// — access individual input/output streams (I/O streams)
zlib:// — Compressed streams
data:// — Data (RFC 2397)
glob:// — Find matching file path patterns
phar:// — PHP archive
ssh2:// — Secure Shell 2
rar:// — RAR
ogg:// — Audio streaming
expect:// — Handle interactive streams